A Novel Thermal Hysteresis-RC Pressure Perturbation Dynamic Characteristic Model of Air Spring Considering the Bending Effects and Energy Dissipation Shifts of Hysteresis Loops

The dynamic characteristics of air springs are mightily hysteresis nonlinear, stemming from the complex structure of the rubber bellows, material nonlinearity, and pressure dependence. This paper aims to precisely capture the dynamic characteristics of air springs, particularly characterizing the pronounced bending effects at the extremes of the hysteresis loop under high amplitudes(>10mm). The friction between the cord and the rubber, the bellows viscoelasticity, and the pressure fluctuations are considered comprehensively. A novel piecewise methodology for characterizing the hysteresis loops is proposed by introducing the resistor-capacitor (RC) operator and pressure parameter. The frequency-dependent Quadratic Parabola Fractional Derivative Kelvin-Voigt Pressure Perturbation Model (QKPPM) is integrated to formulate the RC Pressure Perturbation Hysteresis Nonlinear Model of Rubber Bellows (RCPPM-RB), depicting the evolution laws of model parameters in response to the changes in amplitude, frequency and pressure of rubber bellows. Subsequently, the Thermal Hysteresis-RC Pressure Perturbation dynamic characteristic Model of air spring (TH-RCPPM) under variable working pressure is established. The test results demonstrate that the static hysteresis loops show a maximum relative error of less than 1.6%, with a hysteresis area error of 8.1%. Furthermore, the dynamic hysteresis loop and dynamic stiffness values only have maximum relative errors of 7.1% and 5.4%, respectively. The accuracy and broad applicability of the novel model proposed are verified by experiments. The research results present an innovative approach for accurately modeling the dynamic characteristics of air springs and a fresh idea for the precise characterization of the dynamic characteristics of air springs.